 (defmethod apply-action :new-column [initial-state [_ action]]
   (let [{:keys [id header]} action]
     (assoc initial-state id {:header header :notes {}})))
+
+(defmethod apply-action :delete-column [initial-state [_ action]]
+  (let [{:keys [id]} action]
+    (dissoc initial-state id)))
 
 (defmethod apply-action :new-note [initial-state [_ action]]
   (let [{:keys [id column text]} action]

                                                            (.. e -target -value)))})
                 (dom/button #js {:onClick create-column}
                             "Add column"))))))

(defn create-note-button [app owner]
  (reify

            [id column] column]
        (dom/div #js {:className "column"}
                 (dom/h1 nil (:header column))
                 (om/build delete-column-button {:connection connection
                                                 :column-id id})
                 (apply dom/div nil
                        (map (fn [note] (om/build note-view {:connection connection
                                                            :column-id id
